Molybdenite (MoS2) is a widespread mineral, but occurs exclusively in very few economic deposits. Most commonly, molybdenite is present as an accessory mineral in copper sulphide ores, such as those in porphyry deposits. These deposits become weathered over time, with the more reactive copper sulphide minerals converting to copper oxides, such as malachite and azurite, whilst the molybdenite remains relatively unweathered, remaining significantly as the suphide. There are many copper-molybdenum deposits that have such a weathered layer above the sulphide. The difficulty processing ores comprising a mixture or oxides and sulphides means that the weathered layer is often removed in order to access the underlying sulphides, and remains unprocessed.
Ores containing sulphide minerals can be processed by froth flotation, whereby the sulphides are separated from each other and concentrated. Such a process on a mixed oxide-sulphide ore will result in only the sulphide component being recovered.
In this context, the economic advantage of a process able to recover the metals from both copper oxides and molybdenum sulphides is immediately apparent. There is no present method by which copper oxide—molybdenum sulphide ores can be simultaneously (that is, without a separation step) treated using hydrometallurgical means. Such a process will of course allow economic recovery of these metals from lower grade ores or flotation tailings or residues.
Throughout this specification, unless the context requires otherwise, the term “copper oxide” refers to any non-sulphide copper-bearing mineral or mixture of minerals. Thus, the term copper oxide encompasses copper-bearing minerals containing anions such as carbonate, hydroxide, sulphate, nitrate, chloride and/ or phosphate. Accordingly, although the term copper oxide includes the oxide minerals tenorite and cuprite, it should not be understood to be restricted to such.
Throughout this specification, unless the context requires otherwise, the term “molybdenum sulphide” refers to molybdenum-bearing minerals which may also contain anions such as carbonate, hydroxide, sulphate, nitrate, chloride and/or phosphate, in addition to the molybdenum sulphide minerals.
Throughout this specification, unless the context requires otherwise, the word “comprise”, or variations such as “comprises” or “comprising”, will be understood to imply the inclusion of a stated integer or group of integers but not the exclusion of any other integer or group of integers
The discussion of the background art is included exclusively for the purpose of providing a context for the present invention. It should be appreciated that the discussion is not an acknowledgement or admission that any of the material referred to was common general knowledge in the field relevant to the present invention in Australia or elsewhere before the priority date.